GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS, NET, Intangible Assets, by Type (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020
Intangible Assets [Line Items]
Gross carrying value, finite-lived intangible assets	$ 312	$ 206
Accumulated amortization, finite-lived intangible assets	(90)	(72)
Customer relationships
Intangible Assets [Line Items]
Gross carrying value, finite-lived intangible assets	238	134
Accumulated amortization, finite-lived intangible assets	(79)	(61)
Trade name
Intangible Assets [Line Items]
Gross carrying value, finite-lived intangible assets	12	10
Accumulated amortization, finite-lived intangible assets	(5)	(4)
Seller relationship agreements
Intangible Assets [Line Items]
Gross carrying value, finite-lived intangible assets	4	4
Accumulated amortization, finite-lived intangible assets	(3)	(2)
Other
Intangible Assets [Line Items]
Gross carrying value, finite-lived intangible assets	6	6
Accumulated amortization, finite-lived intangible assets	(3)	(5)
Customer relationships
Intangible Assets [Line Items]
Gross carrying value, indefinite-lived assets	52	52
Accumulated amortization, indefinite-lived assets	$ 0	$ 0